Is it ensure, insure, or assure?
The measuring and analysis of such physical attributes as facial features and voice or retinal scans. This technology can be used to define an individual's unique identity, often for security purposes.
Note: Software is available that can match faces of individuals videotaped on the street to the picture of a suspected criminal or terrorist in a database. The use of biometrics is likely to increase in the future as security concerns become more of a priority for both governments and corporations following the September 11 attacks (2001).